Method of operating gas or shale oil producer-retorts



Dec. 17, 1957 GALUSHA 2,816,823

METHOD OF OPERATING GAS OR SHALE OIL PRODUCER-RETORTS Filed Oct. 20, 1952 5 Sheets-Sheet 1 //7 van for A/berf L .Ga/us/m B y his af/omeys METHOD OF OPERATING GAS OR SHALE OIL PRODUCERRETORTS Filed Opt. 20, 1952 A. L. GALUSHA Dec. I7, 1957 5 Sheets-Sheet 2 F/GZ . D v 1 33* MN w .& 3??

//7|/enf0r A/benL. Ga/usha By his attorneys Dec. 17, 1957 A. L. GALUSHA 2,816,823

METHOD OF OPERATING GAS OR SHALE OIL PRODUCER-RETORTS Filed Oct. 20, 1952 5 Sheets-Sheet 5 Mme/Nor Alberf L. Gar/usher By his aflomeys I METHOD OF OPERATING GAS OR SHALE OIL PRODUCER-RETORTS Albert L. Galusha, Verona, N. J.

Application October 20, 1952, Serial No. 315,737

4 Claims. (.Cl. 48-203) This invention relates to gas producers and shale oil retorts and a method of operating same. The invention is equally applicable to apparatus for producing gas from coal and to retorts for producing oil vapor from shale, which vapor is thereafter condensed. Hereinafter I will refer to apparatus for either purpose as a producerretort. The invention relates more particularly to means for removing the ash refuse and is a continuation-in-part of my copending application Serial No. 207,162, filed January 22, 1951, now abandoned.

One of the objects of the invention is to provide a method for operating a gas producer which will enable continuous production of high pressure gas without boosting the produced gas pressure or cleaning the produced gas. Another object is to provide apparatus which can operate efficiently and continuously under high pressure from blowers and give relatively low, exact firebox temperatures with a minimum of labor in handling the ash or the refuse. Still another object is to provide an apparatus which can use small size, and consequently less expensive, fuels than heretofore.

It is characteristic of my invention that a producer retort having a conical ash-refuse hopper directly beneath a pressured firebox is operated so that when refuse accumulates in the hopper to the extent that some must be removed, only a part of the accumulated ash-refuse is removed by gravity through an aperture in the bottom of the hopper. Thus a wall of ash is maintained between the pressured firebox and the atmosphere, which bars venting of the firebox during ash removal. It is further characteristic of my invention that a producerretort having a conical ash hopper is provided with an ashrefuse water jet and gauge as hereinafter described.

Producer-retorts according to my invention, can be operated continuously, including the ash removal period, without loss of the blower blast pressure in the firebox. They will produce sufficient pressure to enable the gas to be put through a scrubber or cyclone dust collector and then to be distributed to the points of use without the use of a gas pump, or if cleaned gas is not required, scrubber and dust collector can also be dispensed with. The invention will be shown and described embodied in hot gas producers and shale oil retorts, but it should be understood that it is equally applicable in any producer-retort.

In the drawings:

Fig. l is a general diagram of a hot gas producerretort with a dust collector, in which my apparatus has been incorporated;

Fig. 2 is a diagrammatic view in vertical section of a gas producer-retort in operation made in accordance with an improved form of my invention, showing my novel ash spray system; and

Fig. 3 is a cross section fragmentary view of the ashrefuse hopper of the producer-retort of Fig. 2, showing details of operation of the ash spray;

Fig. 4 is a view in vertical elevation through the preferred form of a gas producer retort employed as a shale 2,815,823 Patented Dec. 17, 1957 oil retort, the apparatus showing an agitator in the the box and a scrubber attached to the hot gas outlet.

One of the most desirable features in a gas producer or shale retort is continuous operation. A common commercial type of continuous gas producer and shale retort now in use is one in which there is a revolving water seal pan under the firebox grate. It is necessarily located at ground grade level. To handle and remove ashes, a stationary plow is used in the edge of the revolving water seal pan. This ash removing plow takes the ash up out of the pan, whence the ash drops into an ash receptacle in a pit below ground. Here an attendant loads a small dump car and takes it away. This requires a full time attendant. My new ash and refuse handling apparatus makes it possible to drop the ash or refuse into a full size railroad gondola bottom-discharge car by gravity in a few minutes, once or twice a day, without disturbing the producerretort operation. It eliminates the attendant and ashrefuse handling expense.

Another disadvantage of the water seal gas producer is the matter of pressure. The air for the fire is blown up through the firebox. In order to do this without causing the air blast to blow out through the water seal, thus stopping the production of gas and causing other troubles, the pressure has to be kept low. It is impossible to make the water seal deeper because then the ash cannot be removed properly. When the pressure is kept low enough to avoid a blowout, the gas coming ofif the top of the producer has to be pumped to get sufficient pressure. To pump the gas Without wrecking the gas pump requires washing and drying of the gas at great expense and trouble. For example, the initial cost of washing, drying, and pumping apparatus is more than the initial cost of the gas producer itself. With my apparatus the air fire blast pressure can be as high as desired, and as a result it usually will not be necessary to use a gas pump and gas washing apparatus. For example, my blower can, if desired, deliver the hot gas or oil vapors at more than five-eighths of a pound pressure. The air blowers of prior producers in general deliver less than onequarter of that pressure. In such prior producers, pumps were used to step up the pressure for distribution. However, in order to pump the produced gas, it was necessary to pass it through a scrubber or a cyclone dust collector to prevent sticking and excessive wear of the pumping equipment. My invention therefore not only eliminates the expensive pumping plant, but also the very large expense of having to wash and purify the gas in order to put it in pumping condition.

in operating prior gas producers of another type having output scrubbers and pumps and sometimes called clean gas generators, it has been standard practice to increase the suction of the pump to replace the ash pit air pressure from the blower during ash removal periods. In this way an ash discharge valve can be opened for some time without changing the flow of air through the fire bed. Such a method of removing ashes cannot be used on hot gas producerretorts or on shale oil producer-retorts if the gas pump is eliminated, because there is no substitute for the ash pit pressure which is lost when the ash discharge valve is opened. It being necessary to maintain the pressure in the firebox without any change, even when taking out ash or refuse, I have arranged my ash removal in such a manner that I can employ every minute of the day a powerful blower to blow the air in and thus entirely avoid the use of a pump on the gas output.

in Pig. 1, i have shown a producer-retort more particulariy adapted to generate hot gas. Mounted on concrete bases 1 is a steel framework 2 supporting the gas generator or shale retort 3 at a point elevated above the ground. To one side of the generator or retort 3 is the usual fuel elevator 4 adapted to receive fuel from railroad gondola cars or trucks at the ground grade level and elevate it to the top of the building. From the elevator the coal descends through one or more chutes 6 to a storage bin 7. From this overhead storage bin 7 the coal descends through two or more open feed pipes 8 into the firebox 9 of the apparatus (see Fig. 2). This firebox has a water jacket 20 and a rotary grate 10 near the bottom, all as shown and described in my prior U. S. patent entitled Gas Producer, No. 2,440,940, dated May 4, 1948. As described in that patent, the rotation of the grate results in the ashes gradually being dropped through the grating either around the edge or between the stepgrates.

I supply an air mixture underneath the firebox 9 from a blower 11 which I have shown mounted on the frame of the apparatus just above the firebox. The details of this air blast blower can be seen in Fig. 2 of the drawings, from which it will be observed that the air under pressure from the blower travels across the top of the firebox in the water jacket 20, picking up vapor and forming the air mixture. It then proceeds downward through an intake pipe 12 outside the firebox to a point below the grate where the air mixture is released at a point axially central of the grate. While I have described the mixture which the blower delivers underneath the grate as an air mixture, it should be understood that in place of the ordinary constituents of air and steam it is possible to inject CO oxygen or any other desired material in accordance with the gas or vapor which it is desired to produce from the entire apparatus. From the air-tight firebox the gases resulting from the combustion are taken off at the top through an outlet pipe 13 (Fig. 1), whence, in the example shown in this particular figure of the drawings, the gases pass through a centrifugal dust collector 14. The collector 14 cleans the hot gases and the gases will go out into the distribution system 17 to the point of use from an outlet 18 at the top of the collector.

The blower 11 which I employ is capable of producing sufficient pressure to enable the gas to pass through the collector and still be under sufficient pressure to enable it to go through the distribution pipes to the point of use. For example, I find it convenient in some installations, as already mentioned, to use a gas pressure of 18 inches of Water above atmospheric. The revolving or other kinds of water seal bases of other producers cannot be made deep enough to stand the blast pressure necessary to produce the needed high gas pressures and blast pressures that my apparatus easily produces. It must be recognized that a blowout through a water seal causes loss of the necessary fire blast pressure in the firebox. This results in a cessation of the making of the gas or oil vapors and a dislocation of the sequence of operations which may even result in an explosion. Heretofore there have been only two known ways to remove the ash from the bottom of the firebox without causing this dangerous dislocation of the process of making gas or oil vapors. Both systems have the disadvantage that it is necessary to put in a pump to boost the pressure of the gases or vapors after they have left the cyclone separator or collector, as the case may be, in order to give them enough pressure to travel to their point of use. According to my invention, this pump, with the necessity for cleaning apparatus in order to pump the gases without damage to the gas pump, is entirely eliminated.

Turning now to Fig. 2 of the drawings, I have shown in this figure a vertical elevation in section of the firebox and ash hopper of a producer-retort made in accordance with my invention, containing an improvement not shown in Fig. 1. This improvement relates to the ash hopper. I will first describe the blower and firebox in more detail. This Fig. 2 is taken in a vertical plane at right angles to the showing of Fig. 1 in order to show in more detail the saturation control of the air mixture'put in the firebox by the air blast blower 11. As the blast leaves the blower 4 v it passes through the top part of the water jacket 20 around the firebox. After passing across the top of the firebox, it passes downward through the intake pipe 12 shown at the left of Fig. 2. In this pipe it passes the sensitive element of an external thermometer 21 by means of which the operator can keep track of the temperature of the air mixture and thus of the fire in the firebox. This temperature is very important. Adjustments are made by control means 22 and 23 near the blower. The means 22 are for hand control and means 23 for automatic control. They control the water injected to make steam by pipe means 24 which lie in the water jacket near the point where the air from the blower enters the jacket. The water is obtained from a pipe 25 feeding controls 22 and 23 and a by-pass line 26. The mechanism making the control 23 automatic includes a temperature-sensitive bulb 27 located in the air mixture intake pipe 12 just above the external thermometer 21. This bulb normally con trols the fire temperature acting through a tube 28 connecting it to the control 23. For a fuller description of these means to maintain exact and low temperatures in the producer-retort, I refer to my prior Patent No. 2,185,077, dated December 26, 1939.

The air mixture thus made forms a gaseous pressure filling the entire space between the ash or refuse in the hopper 19 and the ash or refuse on the grate. It blows through the ash or refuse on the grate to the burning material in the fire zone 29. Thence the resultant gases pass up through the coal in the firebox above the fire zone to the outlet pipe 13 at the top of the firebox in Fig. 1. This outlet pipe does not appear in Fig. 2 because it lies at the back of the apparatus as it appears in this figure.

The rotary grate 10 is driven and operates exactly as shown and described in my said Patent 2,440,940. The ash or refuse from the grate falls down into the ash hopper 19. The hopper is cone shaped. At its upper end it is substantially the diameter of the inside of the firebox and at its lower end it is tapered down to a restricted orifice 30. This hopper acts as a storage hopper for the ash or refuse. There is a horizontally movable closure 31 for this orifice. This closure is operated from a hand chain hoist 32 on the frame 2 of the producer-retort to give quick opening and closing of this ash discharge opening. The chain hoist is used to move horizontally a rack and bar 33 to which the closure is attached. In the em bodlment of Fig. 2 the chain hoist is shown on the right side of the frame, while in Fig. 1 the chain hoist is shown at the left.

The accumulation of ash or refuse builds up a bed in the bottom of the hopper through which the blower pressure cannot escape. Therefore when the closure is moved and the restricted orifice opened, gravity, aided slightly by the blower pressure, will begin pushing the stored ash out of the orifice. Experience will enable the operator to tell from the speed with which the ash moves approximately how much more ash is still to come before the ash will cease to occupy the entire orifice. Thus the speed with which the ash moves through the orifice or discharge gate will change slightly as the ash level in the hopper lowers. Furthermore, by timing, a uniform practice can be established. According to the invention, when the hopper is nearly empty, but before the bed of ash has diminished to the point where the blower pressure can penetrate to any substantial extent, the operator closes the discharge gate, thus preventing a blowout and loss of the pressure in the firebox. It will be seen that with this construction and method of operation, there always will be a solid bed of ashes between the bottom of the fire box and the outside atmosphere. In this way the producer-retort canv be kept in continuous action through the ash removal period without loss of blast pressure.

In the embodiment of Fig. 2 a further. improvement is provided for discharging the ash without losing the blower pressure. When using certain varieties of fuel, dry ash refuse will simply not slide down the walls of the conical hopper as desired. It is then necessary for an attendant to reach in with a long hook bar and scrape the refuse loose from the walls of the hopper. This is time consuming, and, in addition, the poking action of the hook bar creates channels through which gases from the hopper can escape causing fluctuations in the output pressure and loss of valuable gases. To avoid this, I provide water jet means to prepare the ash for removal and also to push the ash toward the orifice. Such water jet means comprises a high pressure spray jet or ring 34 around the inside of the hopper 19 near the top of the conical part of the hopper. Details of the spray ring can be seen more clearly in Fig. 4. As shown in that figure, the spray ring 34 is adapted to direct high pressure jets of water downwardly along the cone of the hopper. These jets of water, at a pressure of say p. s. i. g., free any lumps sticking to the metal surface and push them down toward the discharge point. The water also has the effect of solidifying the mass and making it impervious to the blast of the blower. The water is admitted to the ring by pipe 38 under the operators control. In the preferred embodiment of the invention, a water gauge 35 is connected to the top and bottom of the hopper by pipes 36 and 37. In this way, I provide outside the hopper, an indicator of the depth of the water and ash-refuse in the hopper. When using the gauge the operator can continue to admit water through pipe 38 until the gauge shows the desired water level in the hopper. He can then shut off the water and start discharge of the ashes. When the gauge shows the water level near the bottom of the hopper, the closure 31 is moved to the closed position shown in Fig. 2 and the storage of ashes begins again. By timing these water and discharge operations and the interval between discharges, the operator can establish a time schedule and he will not have to refer to the water gauge thereafter.

In the preferred method of operation, the ash is allowed to pile up above the level of the spray ring 34. The spray is then turned on until the water has reached the desired level, below the top of the ash-refuse. The water is then shut off and the hopper closure 31 is opened until the water level has fallen to the desired point. In this way, hot ash from the firebox 20 does not contact water, and steam generation is avoided, allowing constant gas quality to be maintained throughout the ash removal operation.

I elevate the ash discharge orifice sufiiciently to provide space directly underneath for a gondola railroad car or other movable ash removal means. Preferably I locate the orifice high enough above the ground or grade level 5 for a railroad car or truck to be stationed directly under the hopper.

In Fig. 4 I have shown my invention embodied in a producer-retort having an agitator in the fire box, an enlarged ash storage hopper with water jet and gauge means and a scrubber in place of the dust collector of Fig. 1. Such an embodiment constitutes the preferred embodiment of my invention.

The agitator shown in this figure is described and claimed in my U. S. Patent No. 2,502,141, dated March 28, 1950, entitled, Agitators for Gas Producers. It has two horizontal tubular members or arms 40 carried in the firebox by a vertical pipe 41 extending downwardly into the coal. This pipe is rotated and moved vertically by means hereinafter described, thereby giving a spiral reciprocatory motion to the horizontal arms 40. These arms keep the fire broken up and uniformly porous for the draft from the blower. This is important to avoid blow holes which are apt to occur, particularly when the fuel used contains any fines. This is also important when there is any extremely small shale present. It might be pointed out that when there is a blow hole the vapors or gases on top of the fire bed will burn. Also, some kinds of shale are very rich in oil and when melted will cake and form blow holes. The use of my agitator prevents this caking and melting.

The tubular members constituting arms 40 can have caps 42 at their ends. I also provide downwardly in clined wear plates 43 mounted on the arms 40. There is a wear plate extending along the full length of the forward side of each arm considered in the direction of rotation. The interior of the vertical pipe 41 is open to the interior of the tubular arms 40. At the upper end the pipe 41 extends up into the storage bin 7 but in an axially central position where it is kept free of coal by an inner Wall 44. This upper end of the pipe 41 is rotatably supported in a yoke 45 connected by a cable 46 to a suitable counterweight 47 on the outside of the fuel bin 7. The pipe 41 and the horizontal arms 40 are cooled by liquid supplied to an inner pipe (not shown) by flexible connec tions 48. All this is described in full detail in my said Patent 2,502,141.

To rotate the agitator I provide a ratchet wheel 49 fixed on the vertical pipe 41 just below the feed bin 7. The ratchet wheel is actuated intermittently by a rod 50 and pawl 51 driven by a disc to which the crank rod 50 is connected, this disc in turn being driven by motor 53.

To raise and lower the agitator I provide a yoke 54 secured to a nut carried by a rotatable vertical threaded shaft 56 and engaging between collars 57 on the vertical pipe 41. The rotation of this threaded shaft 56, which is vertically immovable, will cause the pipe 41 to move vertically according to the direction of rotation of the threaded shaft. To cause this rotation of the threaded shaft at the proper time, I provide a ratchet wheel fixed on the threaded shaft and a double acting ratchet pawl (not shown) pivotally mounted in a yoke journalled on the threaded shaft. This ratchet is operated from the motor 53 by means of a second crank disc 59 and rod 60, as set forth in my said Patent No. 2,502,141. The vertical and horizontal movements of the agitator are carried on simultaneously so that the agitator is raised and lowered with n the limits of its movement as it is rotated in the fuel bed.

I have shown in this figure, although in the actual producer-retort it occurs in a plane at right angles to the figure, an oflftake pipe 61 at the top of the fire box carrying off the gas vapors to a scrubber 62. The scrubber 62 may be used in the making of producer gas from coal fuel or oil from shale fuel. I will first describe it when used to make oil from shale. In producing oil from shale it may be noted that the shale as fed into the fire box contains no oil. However, when heated in the firebox in a deoxidizing atmosphere to, say, 800 F. or a little higher, chemical changes take place which form crude oil. After this oil "apor leaves the shale there still is carbon left in the shale and therefore the shale in the lower part of the firebox, i. e., in the fire zone 29, is burned to form more oil vapors. The ash or refuse resulting from burning shale is greater in quantity than the ash from coal. Hence I have shown an enlarged ash storage hopper 63.

The shale oil comes off the shale in vapor form and passing through the hot gas offtake pipe 61 enters the bottom of the scrubber 62. Here the shale oil vapor passes upwardly through a porous bed down which cool oil is trickling. This condenses the oil vapor which passes out the bottom of the scrubber into a pipe 15. The cool oil is sprayed on the top of the bed from sprayers 16. The remaining gases pass out of the scrubber to the distribution system 17, as in the case of Fig. 1. If the producer-retort is making producer gas, the liquid used in the scrubber may be water and a gas dryer 64 may be used at the top of the scrubber.

Some shale is of such a nature that it is desirable to discharge the ash-refuse through the grates at temperatures as high as 800 F. It is impossible to use the usual water seal base producer in such cases or even to use water in the bottom of my ash-refuse cone shaped storage and discharge bin. In that case, I use the same ash cone without the water spray means but furnish revolving eccentric step grates, the vertical clearance between which is sufficiently small that the ash-refuse is crushed and broken up so small that it flows down and out almost like water or flows without allowing draft to blow through it. In this case, I use this dry, hot ashrefuse instead of water to seal off my shale refuse discharge opening and prevent loss of draft pressure. This permits me to use my ash discharge without loss of pressure even on ash-refuse as high in temperature as 800 F. One reason why it is desired to discharge the refuse at a high temperature is to discharge it before all of the carbon has been oxidized.

Some of the important improvements resulting from my apparatus and the method of operation of same in making gas from coal or shale or to produce oil from shale are as follows. In the first place, I estimate that I save up to 85% of the labor of handling the ash and refuse. It will be seen that with my system the handling of the coal or shale is entirely automatic from the time the coal or shale drops through the open door in the bottom of a gondola railroad car and enters the fuel elevator 4 until the ash or refuse is dropped by gravity into another railroad dump car. I also am able to use smaller size, and consequently less expensive, fuels to make the same gas or the same oil vapor. My apparatus enables me to deliver hot gas or oil vapors direct from the producer-retort at pressures as high, for instance, as 18 inches of water above atmospheric, which has never been done before. This eliminates the very large expense of having to wash and purify the gas in order that it may be pumped. Despite the fact that shale oil leaves more ash or refuse than coal, I am able to process many more tons of shale per day than any producer-retort heretofore used in the production of shale oil. My ash removal system enables me to use a much higher air blast pressure than can be used with water seal producerretorts. This is one of the primary causes of getting the greater results obtained. It should also be noted that my producer-retort maintains exact and low temperatures in the retort-something which is very valuable in the production of shale oil. If the temperatures in the fire box get too high, the oil is cracked into a gas, which is not desired when retorting shale. My producer-retort not only enables the use of much smaller sizes of fuel by preventing blow holes, but by the use of the agitator ensures the exact, even temperatures necessary and great- 1y increases the number of tons of shale or other fuels that can be processed per 24 hour day.

What I claim is:

1. A method for making producer gas which comprises continuously feeding coal to a horizontal fired bed, continuously passing air at a pressure in excess of A of a pound per square inch gauge upwardly through said bed, continuously removing ash downwardly from said bed and collecting the ash in a normally mechanically sealed downwardly tapered conical receptacle beneath said bed, periodically directing a plurality of water jets downwardly along the wall of said conical receptacle between said wall and the body of collected ash, and below the level of said ash, thereby freeing the ash adhering to said receptacle and moving said ash downwardly in said receptacle, periodically breaking said mechanical seal and withdrawing ash from said conical receptacle, and maintaining the aforesaid pressure in said bed throughout the ash removal period by stopping the withdrawal of ash from 8 said receptacle before all of the ash is removed, and by retaining a sufficient body of ash in said receptacle to seal said receptacle; and restoring the mechanical seal to said receptacle.

2. The method claimed in claim 1 and including the step of removing the ash from said conical ash receptacle solely by gravity.

3. The method claimed in claim 1 and including terminating the operation of said water jets before the mechanical seal is broken.

4. A method for making producer gas which comprises continuously feeding coal to a horizontal fired bed, continuously passing air at a pressure in excess of A of a pound per square inch gauge upwardly through said bed, continuously removing producer gas upwardly from said bed, centrifugally removing dust from said gas and delivering said gas directly to the point of use, in combination with the steps of continuously removing ash downwardly from said bed and collecting the ash in a normally mechanically sealed conical receptacle beneath said bed, periodically directing a plurality of water jets downwardly along the wall of said conical receptacle between said wall and the body of collected ash, and below the level of said ash, thereby freeing the ash adhering to said receptacle and moving said ash downwardly in said receptacle, periodically breaking the mechanical seal and withdrawing ash from said conical receptacle, and maintaining the aforesaid pressure in said bed throughout the ash removal period by stopping the withdrawal of ash from said receptacle before all of the ash is removed and -by retaining a sufficient body of ash in said receptacle to seal said receptacle; and restoring the mechanical seal to said receptacle.

References Cited in the file of this patent UNITED STATES PATENTS 873,647 Young et a1. Dec. 10, 1907 881,549 Clements Mar. 10, 1908 1,006,210 Heid Oct. 17, 1911 1,187,049 Doherty June 13, 1913 1,350,627 Ten Broeck et al Aug. 24, 1920 1,489,905 Stolman Apr. 8, 1924 1,809,501 Allen June 9, 1931 1,819,486 Sherman Aug. 18, 1931 1,857,355 Chapman May 10, 1932 1,901,169 Karrick Mar. 14, 1933 1,922,321 Parker Aug. 15, 1933 1,924,819 Van Ackeren Aug. 29, 1933 2,031,578 Wilgus Feb. 18, 1936 2,185,077 Galusha Dec. 26, 1939 2,255,375 Blake Sept. 9, 1941 2,381,200 Blake Aug. 7, 1945 2,440,940 Galusha May 4, 1948 2,477,390 Pisters July 26, 1949 2,502,141 Galusha Mar. 28, 1950 FOREIGN PATENTS 385,575 Germany Nov. 26, 1923 OTHER REFERENCES Chemistry of Coal Utilization, H. H. Lowry, vol. II, John Wiley & Sons (N. Y. 1945) pages 1659-1666.

Oxygen Gasification of Anthracite in the Wellman- Galusha Producer Proceedings, Amer. Gas. Assn. (N. Y. C. 1947) pages 701-709.

Wellman-Galusha Gas Producers, The Iron and Coal Trades Review (London) Feb. 20, 1931, pages 318 and 319. I v 

1. A METHOD FOR MAKING PRODUCER GAS WHICH COMPRISES CONTINOUSLY FEEDING COAL TO A HORIZONTAL FLRED BED, CONTINOUSLY PASSING AIR AT A PRESSURE IN EXCESS OF 3/4 OF A POUND PER SQUARE INCH GAUGE UPWARDLY THROUGH SAID BED, CONTINOUSLY REMOVING ASH DOWNWARDLY FROM SAID BED AND COLLECTING THE ASH IN A NORMALLY MECHANICALLY SEALED DOWNWARDLY TAPERED CONICAL RECEPTABLE BENEATH SAID BED, PERIODICALLY DIRECTING A PLURALITY OF WATER JETS DOWNWARDLY ALONG THE WALL OF SAID CONICAL RECEPTABLE BETWEEN SAID WALL AND THE BODY OF COLLECTED ASH, AND BELOW THE LEVEL OF SAID ASH, THEREBY FREEING THE ASH ADHERING TO SAID RECEPTACLE AND MOVING SAID ASH, DOWNWARDLY IN SAID RECEPTACLE, PERIODICALLY BREAKING SAID MECHANICAL SEAL AND WITHDRAWING ASH FROM SAID CONICAL RECEPTACLE, AND MAINTAINING THE AFORESAID PRESSURE IN SAID BED THROUGHOUT THE ASH REMOVAL PERIOD BY STOPPING THE WITHDRAWAL OF ASH FROM SAID RECEPTACLE BEFORE ALL OF THE ASH IS REMOVED, AND BY RETAINING A SUFFICIENT BODY OF ASH IN SAID RECEPTACLE TO SAEL SAID RECEPTACLE; AND RESTORING THE MECHANICAL SEAL TO SAID RECEPTACLE. 